The Dark Matter Contribution to Galactic Diffuse Gamma Ray Emission

Abstract

Observations of diffuse Galactic gamma ray emission (DGE) by the Fermi Large Area Telescope (LAT) allow a detailed study of cosmic rays and the interstellar medium. However, diffuse emission models of the inner Galaxy underpredict the Fermi-LAT data at energies above a few GeV and hint at possible non-astrophysical sources including dark matter (DM) annihilations or decays. We present a study of the possible emission components from DM using the high-resolution Via Lactea II N-body simulation of a Milky Way-sized DM halo. We generate full-sky maps of DM annihilation and decay signals that include modeling of the adiabatic contraction of the host density profile, Sommerfeld enhanced DM annihilations, $p$-wave annihilations, and decaying DM. We compare our results with the DGE models produced by the Fermi-LAT team over different sky regions, including the Galactic center, high Galactic latitudes, and the Galactic anti-center. This work provides possible templates to fit the observational data that includes the contribution of the subhalo population to DM gamma-ray emission, with the significance depending on the annihilation/decay channels and the Galactic regions being considered.

Published by PRD

References in corpus (10)

• A Theory of Dark Matter
• Dark matter and cosmic structure
• Constraining Light Dark Matter with Diffuse X-Ray and Gamma-Ray Observations
• A blueprint for detecting supersymmetric dark matter in the Galactic halo
• Constraints on the Galactic Halo Dark Matter from Fermi-LAT Diffuse Measurements
• The Dark Matter Annihilation Signal from Galactic Substructure: Predictions for GLAST
• The shapes, orientation, and alignment of Galactic dark matter subhalos
• Galactic Substructure and Dark Matter Annihilation in the Milky Way Halo
• Stringent Constraints On The Dark Matter Annihilation Cross Section From Subhalo Searches With The Fermi Gamma-Ray Space Telescope
• Constraints on WIMP Annihilation for Contracted Dark Matter in the Inner Galaxy with the Fermi-LAT

Cited by in corpus (2)

• Constraints on annihilating dark matter in the Omega Centauri cluster
• Does the gamma-ray signal from the central Milky Way indicate Sommerfeld enhancement of dark matter annihilation?